package cloud.pangui.core.utils;

/**
 * 转义字符工具类
 *
 * @author bianrongjun
 * @version 1.0
 */
public class URIUtils {

	/**
	 * 将字符串转成转义字符串
	 *
	 * @param str 字符串
	 */
	public static String encode(String str) {
		int i;
		char j;
		StringBuilder sb = new StringBuilder();
		sb.ensureCapacity(str.length() * 6);
		for (i = 0; i < str.length(); i++) {
			j = str.charAt(i);
			if (Character.isDigit(j) || Character.isLowerCase(j) || Character.isUpperCase(j))
				sb.append(j);
			else if (j < 256) {
				sb.append("%");
				if (j < 16)
					sb.append("0");
				sb.append(Integer.toString(j, 16));
			} else {
				sb.append("%u");
				sb.append(Integer.toString(j, 16));
			}
		}
		return sb.toString();
	}

	/**
	 * 将转义字符转换成字符串
	 *
	 * @param str 字符串
	 */
	public static String decode(String str) {
		StringBuilder sb = new StringBuilder();
		sb.ensureCapacity(str.length());
		int lastPos = 0, pos = 0;
		char ch;
		while (lastPos < str.length()) {
			pos = str.indexOf("%", lastPos);
			if (pos == lastPos) {
				if (str.charAt(pos + 1) == 'u') {
					ch = (char) Integer.parseInt(str.substring(pos + 2, pos + 6), 16);
					sb.append(ch);
					lastPos = pos + 6;
				} else {
					ch = (char) Integer.parseInt(str.substring(pos + 1, pos + 3), 16);
					sb.append(ch);
					lastPos = pos + 3;
				}
			} else {
				if (pos == -1) {
					sb.append(str.substring(lastPos));
					lastPos = str.length();
				} else {
					sb.append(str.substring(lastPos, pos));
					lastPos = pos;
				}
			}
		}
		return sb.toString();
	}

}
